C16 Angler Battery Move: some questions

[Steve-in-SEA]

Hi Folks - thanks in advance for any advice you might be able to offer this new owner.

I'd like to move my (sole) battery to the cuddy in my 16' Angler (for better weight distribution).

I've read every forum article I could find on this common topic... so I'm hoping these questions are specific, make sense, and help the next person contemplating a similar project

I've spent some time inspecting the existing wiring, and have come up with a proposed design (schematic: https://photos.app.goo.gl/hXs3VQbpdGMrmahX9) for the relocation (apologies in advance for my handwriting. In that schematic, these are the existing components I'd re-use: battery, battery switch, house breaker, fuse panel, bilge pump. The house load is what you'd expect: radio, plotter, lights, wipers.

Questions/Requests for comment:
1) Gauge: If I'm reading the specs correctly, my 2005 Honda F50 specifies a battery with a CCA rating of 420 amps. I can't imagine that 50HP motor drawing that much when cranking, so I feel like I'm missing an important detail somewhere. The existing short wires to the motor don't appear to be more than #4 or #6. The new run will be at least 8' farther, so doubling that and rounding up gets me to ~20'. Seems like #2 gauge wire would be sufficient, presuming the actual current draw is more like 100 amps, according to the 3% drop chart here: https://www.westmarine.com/WestAdvisor/Marine-Wire-Size-And-Ampacity. Thoughts?

2) Fusing the #2 wire: in the new configuration, the battery and switch will be 8' from the motor. Seems like I should protect that long of a run with a fuse near the battery. Thoughts? If so: any recommendations on a high-load fuse that can handle cranking?

3) Powering the pump: In the current arrangement, a ground wire goes directly from the battery to the pump, and two other wires run forward to the dash-mounted switch. It *seems* to me that the pump is therefore powered only when the battery switch is ON. I need to double-check this, but if so, this seems incorrect? Shouldn't the bilge pump always be powered?

4) Use of "Distribution Stud": I'm considering using something like this to simplify the high-power connection between the Honda's existing wiring and the new #2 run from the battery: Honda 33000-ZY3-000AH https://marine.honda.com/parts/accessories/categories/battery-management. Any thoughts or recommendations?

5) Securing the battery: As you may know, the floor of the C16 Angler cuddy is flat and carpeted (photo: https://photos.app.goo.gl/m7BgF3Stf2DAt3x69). My plan is to screw the battery tray directly into that floor, on the port side. The floor has other things already screwed into it, including a tie-down strap identical to the one at the stern currently being used to tie down the battery. Any advice on this plan? I realize that the bow moves more than the stern, so I'm wondering whether the 67 pound battery would warrant special mounting considerations...

Thanks again for any advice re: the above questions... or anything else you see that I'm missing here

 

[Marco Flamingo]

Steve,

I did the battery relocate thing on my 16 Cruiser.

1) Gauge: On the cruiser model, it was possible to put my batteries under the passenger seat box, so my run is probably less than what you will need. Even still, my battery cables run from the passenger seat down the port side and across under the splash well to the existing battery switch on the starboard side. I think that was a 20' round trip. I don't remember what gauge I used, but I remember seeing that the initial draw at startup for my Yammi 50 was significant. I'm not at the boat right now, so can't check what I used. Also, there is nothing to say that I did it right, only that the gauge I used worked for me.

I do remember seeing the crazy price for tinned wire. I went to Tractor Supply and bought untinned wire and then was very careful to completely seal up the soldered on fittings, etc. I wasn't going to pay for 20' of tinned wire when it is only an inch on each end that needs tinning.

2) Fusing: I have a fuse right at the battery stud. I think that mine is one that can be reset. The required amperage is dependent on what gauge wire you choose.

3) Bilge pump: I don't know if there are different requirements for trailered boats. My C Dory is wired so that manual is manual and automatic is only automatic if the circuit is powered. At the survey on my big boat, I was told that the bilge pump should be wired so that it is always on automatic even if the main DC is turned off at the panel. It probably isn't a matter of owner preference and maybe others will provide guidance.

4) No recommendations.

5) Securing the battery: I would advise not screwing anything to the floor ever. If your boat has had the battery screwed to the aft cockpit floor, you should review my photo album on "Balsa Core Issues."

Yes, your battery will definitely need to be secured when placed in the bow. I would study whether it would be possible to build a battery box out of something like Azec plastic lumber (cheaper and lighter than Starboard) and have the box screwed to the bulkhead (and maybe also jammed into place). That is basically what I did for relocating my batteries. I built a platform that tightly fit under the passenger seat and then secured the batteries to that. Mine can all be removed with some effort, but it fits like a puzzle and there are no screws into the boat. Some additional Azec projects are in my photo album under "Modifications: Cabinetry."

 

[Steve-in-SEA]

Marco - thanks very much for the info & advice!

I thought I'd share some additional info, in case it helps other folks.

Question #1 - Regarding Gauge: I emailed Honda support... and they answered within an hour (!):

- Honda engines come with battery cables, a BF50A model would have cables about 12 feet long
- Cranking amps are 200 or less.
- The actual size is metric but it is close to a #4 AWG

I did notice that in the current installation, there's an excess of the factory cables, tied up & out of the way.

I don't know if it amounts to "about 12 feet". In fact, subsequent research indicates it might be more like 8'.

If it really is 12', it might just reach the battery in its new location.

IF the stock wire bundle isn't long enough... I could run new #4 wire and trim the stock cable accordingly, to keep the total length down.

Or, I guess, run the new wire directly into the motor housing and connect it to the starter, to reduce the # of connections?

I wonder if the Honda stock wire is manufactured to be extra flexible for that always moving boat <-> motor interface?

I also wonder if it would be worth going to #2 just to be conservative?

Question #2 - Battery Fuse: thanks for the advice. I did some research, and it seems that #4 wire is rated for 160 amps (source below). So I'll size the breaker for that.

Thanks for other advice and excellent photo resources! Our C16 "Behemoth" could learn a few things from "Limpet"


* Gauge->Amp table: http://assets.bluesea.com/files/resources/instructions/6956.pdf

 

[Steve-in-SEA]

Here's an update on this project, in case the info might prove helpful to others considering something similar.

Cuddy:
- Battery in bolt-down frame (West Martine #17549718)
- 150A fuse in holder (Blue Sea MEGA® / AMG® Safety Fuse Block)

Stern:
- Distribution Stud Module (dual) (BEP 702-2S)
- Battery switch
- 50A breaker for house power

Wiring:
- #2 battery wire connects battery and fuse in the cuddy to battery switch and distribution stud in the stern, to which the engine wires also connect.
- House power comes off the stud and through the 50A breaker, and then on to the cuddy via #12 wire
- Sump pump positive wire also connects to the distribution stud. (This means that the pump can only turn on when the battery switch is on.)

Securing the battery:
- Battery tray holds the battery down from the top. Tray itself is screwed to 1/2" starboard, which is then screwed to the plywood floor of the cuddy.
- Starboard will also be braced against the bulkhead
- Terminal insulators/covers will also be installed

See photo of not-yet completed battery box:


Comments welcome.

Thanks everyone for your help!

 

[thataway]

I am wondering why you didn't just take the console power off the battery after the fuse block in the cuddy? less distance to electronics. Is this a single battery installation? Is there a battery charger?

If the boat is left "out in the open in the water" you want the bilge pump to automatically come on when the water rises in the bilge.

 

[Steve-in-SEA]

Hi Bob - thanks for your comments/questions! Much appreciated.

My answers are below; feedback welcome:

I am wondering why you didn't just take the console power off the battery after the fuse block in the cuddy? less distance to electronics.

I went back and forth on this, and in the end decided that I wanted to be able to use the battery switch to cut power to everything in the boat. This is how it had been wired initially, and I liked the peace of mind.

The measured voltage at the console fuse box (lights, chartplotter, etc) is 13V, about the same as the battery currently.

I guess an alternative is to wire in a master console power switch?

Is this a single battery installation? Is there a battery charger?

Single battery, no charger.

If the boat is left "out in the open in the water" you want the bilge pump to automatically come on when the water rises in the bilge.

Understood. Currently, it's only used for day trips and spends its nights on a trailer... so I opted again for simplicity around that battery switch: "off" is off for the entire boat.

This is a change from the original setup, where the sump pump was indeed directly connected to the battery. And presumably it was like that for all of it's previous years. During my brief ownership so far, nothing bad has come of it (i.e., the battery has held a strong charge, so there's no evidence that, for instance, the pump was turning on randomly while trailered for weeks at a time, etc.). So, to be fair, maybe I'm fixing something that wasn't broken...

It would be very easy to revert back to original functionality, since the battery switch and distribution stud are next to each other.

Sounds like maybe that would be a good move...

Thanks again for the feedback!